I've been having problems where whenever I prune one of my rose bushes, often one of the branches is burrowed into by a nasty cane borer, meaning I have to cut back the rose even further. I'm trying to control the problem by applying PVA to the exposed canes just after they're cut, but I'm worried this is bad for the rose.

Is there anything I can do to prevent these insects from attacking the plants? It has affected multiple bushes and killed off a gooseberry by now. I don't have photos of the damaged plants, as I've cut off the affected canes.

Is it mulched? If yes, with what? A clear photo of an affected plant & the soil area around it would be useful (as least I believe so), as it could lead to suggestions on how you might be able to improve things, help prevent the possibility of disease or pest infection in the future.
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Mike PerryJul 15 '11 at 15:11

spraying your roses with an insecticide or, if you prefer to take the organic route, with a solution of soap and water which is fairly effective.

I understand your concern that the glue/PVA might be harmful, but as household glue (a synthetic resin glue, such as UHU, that is non-toxic to humans but might be toxic to plants) is widely recommended, it is likely to be safe, and it might be better to use this rather than the PVA.